Automatic fire-alarm



.J. W. GRIFFITH, AUTOMATIC FIRE ALARM.

APPLIOATION FILED MAR. 28, 1910.

Patented 111111111911.

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Elm/112141301 Fig-5 1 dam 1111111 111 J. W. GRIFFITH.

. AUTOMATIC FIRE ALARM. APPLICATION FILED MAR. 28, 1010,

Patented Mar. 7, 191 1.

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MICF ME XAB.

'. device of that knid'including .of Tennessee, have-invented I -useful Improvements in Automatic Fire-g Alarms; and I do hereby declare the following to bee. full, clear,

JOHN w. GRIFFITH, or GREENFIELD, TENNESSEE.

AUTOMATIC FIRE-ALARM To all whom may concern:

.Be'it known that I, JOHN W. GRIF ITH.

a citizen-ofthe United States. residing at Greenfield, in the county of Weakley, State and exact description of the invention, such as will enable others skilled infthe art to whichit appertains to make and use the same. 1

This, invention relates to. improvements in fire alarms and more particularly to what isknown asthe automatic type of fire alarms.

It'has for itsobject the provision of a a normally open electric circuit and a c rcuit'closing rodheld in moperative position and so arranged that in event of fire certain mechanism will be operated to release the circuit a closing rod so that the latter will move to circuit closing position, whereby the alarm will be sounded. v

W'ith these and other objects in. view as will more fully hereinafter appear, the resent invention consists in certain novel etails of construction and arrangement of parts, hereinafter .fully described, illustrated in theac'companying drawings and more articularly pointed out in the appended claims; it 'being. understood that variouschanges in the form, proportion, size and minor details of; the device may be made without departing from the spit-1t or sacrificing any of the advantages of the invention; p p

In the accompanying drawings forming art of the specifications-Figure 1 is a ont elevation of the device and showing a diagrammatic view of the circuit. ,Fig. 2 is a sectional plan view approximately on the line-2'-2 of Fig. 1. Fig. 3 is a detailed perspective of the keeper and receptacle for the powder employed to actuate the keeper.

Fig. 4 is a sim lar view of one end portion of the circuit closing rod. Fig. 5 is a front elevation of a modified form ,of the device. Fig. 6 is alan view oft-he same. Fig. 7 isa detaile' perspectiveot the caslng containing the spring ior soundlngthe slgnal.

Similar numerals of referencelare employed to designate corresponding parts throughout.

As shown in Fi 1 the device is applied to the side wall-:0 a room or building'and Specification of Letters Patent. I Application filed March 28, 1910. Ser1aI No. 551,930..

certain new and bellis established Patented MarHY, 1911.

i the alarm located at adistance from the While I have shownbut one signal same.- or alarm it must be understood that Ifam not to be limited to this specific number since it will: be understood, from what will appear later, how any number of alarms or signals might be employed and located at various places without departing from the spirit of the invention. v

The batteries for generating the electric .current are designated in general by the numeral 5 and the alarm. or signal hell by the numeral 6; electric connection bet-ween one pole of the battery and-one pole of the means of a conducting Wire 7 while a similar conducting wire 8 has one end .connected to the-opposite ter- ='minal of the battery and its free end leads to a. position'adjacent the device, forming the subject matter of the present invention and to be presently described. A'conducting wire 9 has one terminal secured to the opposite pole of the bell and its free end leads to a point in juxtaposition with the free terminal of the-wire 8. With this construction it is evident when the terminals of the conducting Wires 8 and 9 are brought j into contact the circuit will be completedand the bell sounded.

What" will subseqi'lently 'be termed a circuit closing rod isdesignated by the nua meral 10. This member is slidinglyffitted in a pair of guides 11 and 12 secured to the side wall of a room or building or other support. The circuit; closing rod at one end is provided with an enlarged head 13. The head 13 is formed. of glass'or other insulating material and the terminal of said'head is provided with a grove '14, correspondin in depth to approximately one-half the di ameter of the conductin wire .8. The free 'end of the conducting wire 8 is desi ned 'toenter this grove so that accidental d s lacement from. the circuit closing ,rod w1ll 'be prevented. The intermediate portion ofthe circuit closing rod or that located between the guides 11 and 12 is provided 'with-afixed flange or collar 15, and encircling that portion of the rod between the collar 15 is a helical compression spring 16, the opposite terminals of which bear on the collar 15, and the aide 11, or that farthest re.- moved from this construction it is evident when the spring is compressed, by virtue of moving t he insulating head 13. With ahead end'of'the rod'toward itsadjacent what contracted opening 18, while its upper guide, the terminals of the circuit will be" operative. position until it is necessary to close the circuit and give the alarm as 111' case of tire the following construction is employed: t

By reference now to Figs. 1 and 3 it -will be seen that secured tothe side wall or other support is a metallic casing 17. The lower end of this casing is provided with a someend is provided with a cover 19, having an enlarged central opening 20. The casing is arranged" a trifle above the horizontal plane of the circuit closing rod 10 and is designed to contain a quantity of powder or explosive substance. I w

By reference now to Figs. 1 and. 2 it will be seen that pivoted to the side wall or other support and at a point removed from that side of the casing remote from the circuit closing rod is one end of what will subsequently be termed a keeper 22. This member "is preferably formed of' a, single piece of bar iron or similar material and on its lower stud 23,'wh'ich is adapted "to nicely fit within the enlarged opening 20, in the cover of the casing, it being understood that the keeper is positioned slightly above the plane of the casing. That and of the circuit closing rod remote from the head 13 is provided with an enlarged disk 21, the upper side of which is a trifle above the plane of the hasing 17, and the free end'of the keeper 22 terminates in a downward extension 25, adapted to engage with one face of the disk 24. The relative positions of the parts are such that when the circuit closing rod is moved toward the casing 17 so as to maintain the rod in inoperative position, the free end of the keeper 22 will engage with the disk 24, and hold the rod in inoperative'po-- sition against the action of the spring 16.

As before stated, when the parts are so positioned, the stud 23TVlll extend through the I opening 20 in the top or cover of the easing. A suitable fuse 26 is insert-ible through the opening 18 in the' lower end of the casing and is embedded in the powder 21. The free end of this fuse may be extended in any direction or it may terminate in branches to cover certain portions of the walls or ceiling of the room.- Thus it will be seen in case of fire the fuse will be ignited when the flame reaches the latter, whereby the powder within the casing will be ignited and explode, thus forcing the stud 23 and keeper upwardly and outwardly. This upward and outward moveside is provided with 'a lateral e v ment "of the keeper will release the circuit closing rod, whereby the latter, by virtue of the spring 1 6, will move to closing position'an'd the alarm sounded. The termi nal ofthe conducting wire opposite to the terminal in engagement with the head 13 is supported against movement by means-of a rod 27, which is held against movement in a-pair of brackets 28 and 29. secured to the side wall and in a plane with the guldes 1,2

. and 13'. One terminal of therod 27 is provided with an insulated head 30 having a groove for the reception of theterm'inal bf the wire9. Thus it will be seen when the parts move to circuit- ;closing. position the said circuit will not beaccidentally. opened such as might occur were the conducting wire 9 notrigidly held.

In the modified form illustrated-in Figs. 5 to 7 inclusive thepar'ts are ,thesame w1ththe exception that a spring actuated alarm is employed in connection with the electric operated alarm. In th'is'instance a casing 31.

is provided, the said casing being preferably formed of hell metal and in two sections. A shaftextends through the central. por tions of the said sections and atone end tel.

minates in a toothed-wheel 33, which is arranged inadvance of theouter section. The. opposite terminal of the shaft 1s providedwith a downward ergtension 34. That portion of the shaft within the casing, has-secured thereto one terminal of a coilspring, (not shown), the said coil spring being suitably connected to a clock work wit-hinf the casing, the latter being provided with a". striker to vibrate against the sections when the spring is released, Since the bell just described; forms no partof the present in-. vention, a detailed description of its parts need not be given since it will be understood that. any form of spring operated ,bell may be employedin connection .withthe device. The casing 31 is held spaced from the adjacent wall by bracket feet 35, so that the end ioa of the shaftprovided with an extension 342 7 may be brought into engagement with the circult closing rod 36, it being understood that the extension 34; is of greater length:

than the width of said bracket feet soljthat when it extends vertically downward. as

shown in Figs. 5 and (3, its lower .endfwill I extend-below the bracket feet. The keeper. 37 is supported from the shank,38 whichis.

arranged a trifle above theplane offthe bell v casing and extends considerably in advanced of the latter so that the free end gfthe'l keeper which provided with adown-turned extension 39 may engage with thetoothed, wheel '33, at the outerend of the shaft32.

Like the keeper 22 the last described keeper 37 is provided on .its lower'side with a medi-, ally arranged stud 40 to enter the opening. at the top of the casing 4.-1.

. In setting the parts, just describedp the circuit closing rod is moved against the action of its spring until the disk 43'at its inner end is in engagement with the down turned extensionB l: of the shaft 32. When the parts are sopositioned the extension 39 at the free end of the keeper 37 is brought lnto engagement with the toothed wheel 33,'

whereby longitudinal movement of the circuit closing rod will be prevented until the powder in the casing 41 is exploded by the burningof the fuse 44, whereby the keeper willv move upwardly and outwardly, from engagement with the toothed wheel 33. When this takes place, it being understood that the spring withinthe casing has been wound the extension 34 on the shaft 32 will rotate away from the disk 430i. the circuit closing I rod, whereby the latterwill move to circuit closing position and sound the alarm at a distance simultaneously with the spring actuated alarm. Thus it will be seen that I have provided a device which is exceedingly simple in structure and comparatively inexpensive to manufacture, embodying few parts and these so arranged that the danger "of derangement will be reduced to a mini.-

mum. i

What is claimed as new, is z- 1. In a fire alarm, a normally open ele ctric circuit, the terminals of the conducting wires of which are arranged in juxtaposition,

a springactuated'circuit closing rod having one end in engagement w1th one of the conducting wires, a casing containing an explosive substance, and a keeper havmg a por-.

tion seated within the easing and one end in engagement with the circuitclosing rod and operating to hold the latter in inoperative position.

2. In a fire alarm, a normally open elec tric circuit, the terminals of'the. conducting wires of which are arranged in juxtaposition,

"a spring pressed circuit closing rod. being position.

provided at one end with a head of insulating material having agroove for the reception of the terminal of one of said conducting wires, a casing containing an explosive substance and a keeper having a portion seated within the casing and one end in engagement with the circuit closing rod and operating to hold the latter in inoperatlve 3 In a. fire alarm, a normally open electric c11'cu1t,the terminals of the conducting wires of which are arranged 1n uxtaposition, a spring pressed circuit closing rod having one end in engagement with one of said conducting wires, "a casing containing an explosive substance located adjacent said rod, and a keeper having one end pivoted at a point adjacent said casing and provided with a stud seated in one end of the casing, the free end of said keeper being in engagement with the circuit closing rod and operating to hold the latter containing an explosive substance located adjacent the movable rod and a keeper having a portion seated in said casing, and provided at one end with an extension to engage that end of the movable rod and serving to hold the latter in inoperative position.

In testimony whereof, I afiix my signature,

in presence of two witnesses.

JOHN w. GRIFFITH.

Witnesses S. G. ABERNATHY,

JNO. B, MCADAMS. 

